1. Field of the Invention
The present invention is in the field of chemical lasers, and in particular relates to a gas-phase iodine laser.
2. Description of the Prior Art
Chemical lasers are devices that derive their population inversions from exothermic chemical reactions, whether directly or indirectly, and include photochemical-induced bond dissociation, radiative recombination of atoms or molecules, and energy transfer processes. In view of their generally efficient conversion of chemical potential into laser radiation, chemical lasers have been sought after for numerous applications in which lightweight, self-contained lasers are utilized.
In 1978 McDermott and co-workers demonstrated the first chemically-pumped electronic transition laser (W. E. McDermott, et al., Appl. Phys. Lett. 32, 469, (1978) and D. J. Bernard, et al., Appl. Phys. Lett. 34, 40 (1979).) Continuous wave (cw) laser oscillation was achieved on the I*(2P1/2)xe2x88x92I(2P3/2) transition via the energy transfer reaction between the oxygen metastable, O2(a1xcex94), and a ground state iodine atom, I(2P3/2). This chemistry forms the basis of the high-powered Chemical Oxygen Iodine Laser (COIL), which operates in the near infrared at 1.315-xcexcm with cw power of up to 40 kW.
The current method for generating chemically pumped, continuous wave iodine lasing at 1.315 xcexcm requires a heterogeneous mixture of chlorine gas and an aqueous peroxide-based solution to generate the I*(2P1/2) lasant species. The COIL, the laser currently deployed in the Airborne Laser (ABL), uses this chemistry to generate atomic iodine lasing at 1.315 xcexcm. It is based on the following chemical mechanism,
2O2Hxe2x88x92+Cl2xe2x86x922Clxe2x88x92+H2O2+O2(a1xcex94)xe2x80x83xe2x80x83(1)
nO2(a1xcex94)+I2xe2x86x92O2(3xcexa3)+2I(n=2-5)xe2x80x83xe2x80x83(2)
xe2x80x83O2(a1xcex94)+Ixe2x86x92I*+O2(3xcexa3)xe2x80x83xe2x80x83(3)
I*(2P1/2)+hxcexdxe2x86x92I(2P3/2)+nhxcexd (1.315 xcexcm LASER radiation),xe2x80x83xe2x80x83(4)
The principal limitations of this device are derived from the aqueous (H2O based) chemistry and include the following system disadvantages: the aqueous peroxide solution is heavy and reduces device efficiency; water (H2O) quenches or destroys the I*(2P1/2) lasant material; aqueous chemistry is inefficient in zero gravity environments; and heat from chemical reactions is retained in basic hydrogen peroxide mixture.
As such, to make the COIL laser viable and robust in all environments (ground, air and space), extensive engineering is required to accommodate the aqueous chemistry. One approach to mitigate these drawbacks is to design an all gas phase laser system that eliminates the waterbased chemistry, the subject of the present invention.
The continuous wave All Gas Phase Iodine Laser (AGIL), is based on a chemical energy transfer reaction between gas phase metastable NCl(a1xcex94) molecules and ground state I(2P3/2) atoms. The NCl(a1xcex94) molecule transfers its electronic energy to a ground state I(2P3/2) atom with resultant continuous wave (cw) laser action on the electronic I*(2P1/2)xe2x88x92I(2P3/2) transition of atomic iodine at 1.315 xcexcm. The invention uses the gas phase chemicals He (Helium), NF3 (Nitrogen trifluoride), DCl (Deuterium chloride), HI (Hydrogen iodide) and HN3 (Hydrogen azide) of suitable substitutes.